Is there a way to bounce emails with certain words in?

I am selling email address such as me@FantasticGrandChild.com and would like to protect the children from any "obscenity spam"

Can I do this for only certain domains, or does it have to be server wide?

You can do this with procmail rules.

Read http://www.uwasa.fi/~ts/info/proctips.html you'll find everything you need to create your rules...

Many thanks. top man!